Safer chemicals studied for oil spill cleanup

Monday

Jan 7, 2013 at 7:01 PM

Scientists with the LSU AgCenter are trying to develop more environmentally friendly chemicals to help clean up future oil spills.

Nikki BuskeyStaff Writer

Scientists with the LSU AgCenter are trying to develop more environmentally friendly chemicals to help clean up future oil spills.Dispersants, chemicals used to break apart oil slicks and dissipate them into the water, caused controversy during the 2010 BP oil spill in the Gulf.Over a period exceeding 12 weeks, BP used more than 1.8 million gallons of the dispersant Corexit to break up the oil into tiny droplets. More than 770,000 gallons of the chemical were used at the oil’s source on the ocean floor.Studies have shown dispersed oil is more toxic than either oil or dispersants alone, said LSU AgCenter wetlands biologist Andy Nyman. Its toxicity is longer lasting, possibly as long as six months based on laboratory studies.LSU AgCenter scientists, working with researchers from Columbia University and Iowa State University, are working to create and test a new less-toxic chemical called a surfactant. Surfactants, one of the most-important ingredients in oil-spill dispersants, allow oil to dissolve in water. They can also be found in many household products such as shampoo or dishwashing soap.In Louisiana, Nyman and Chris Green, an LSU AgCenter toxicologist, are testing the chemical’s toxicity on killifish, a baitfish also known as cocahoe minnows, found in the Louisiana marshes.Killifish is a good species for testing because it adapts to a wide range of salinity, and other scientists have used it for toxicity testing, Green said.The $211,000, three-year study is being paid for by the U.S. Environmental Protection Agency and the National Science Foundation.The project was in reaction to the BP oil spill and the need for a more effective and environmentally friendly dispersant, Nyman said.Finding greener surfactants could also benefit people’s everyday lives, Nyman added.“It’s even bigger than spills because what I’ve come to realize is that these surfactants are not just in dispersants, they’re in a lot of household products we use every day,” Nyman said. “It could help to reduce the toxicity of many products we use.”Green said he has also been testing the toxicity of more common surfactants and household products, such as dishwashing detergent, on killifish. Those results are not yet published.Iowa State researchers are making a new surfactant through a fermentation process using bacteria, soybean wastes and bagasse, fibrous residue from crushed sugar cane stalks. They are working to make the fermentation more efficient, while Columbia researchers are studying the effectiveness of the surfactant’s potential to disperse crude oil.Scientists still aren’t sure why dispersed oil has been found to be more toxic than oil or dispersant alone. But Nyman said he suspects it may be because dispersants break up the oil into the water, exposing marine animals to a lot more oil at once and overwhelming the body’s ability to process it.Scientists will also be looking at surfactant molecules to figure out what makes them toxic and whether their shape has anything to do with their toxicity.The research will not produce immediate results that can soon be used commercially, Nyman said. “This is very preliminary research. I think we’re a decade or two away from seeing something in the marketplace,” he said.LSU AgCenter officials said they’re also planning a mobile lab this year to demonstrate the toxic effects of surfactant chemicals, crude oil and common household detergents using fish and larvae. That will help raise awareness of the project and the benefits of developing safer dispersants.During the spill, the use of dispersants to break down oil was presented as a trade-off. Oil was dispersed into the Gulf to avoid what officials feared could be worse environmental damage if large slicks of oil came on shore into sensitive wetland and beach habitats.“We’re not trying to say the use of dispersants was necessarily a bad thing. In some situations they may be needed,” said Brian LeBlanc, LSU AgCenter and Sea Grant coastal ecologist. “We’re simply trying to develop less toxic, more effective methods of dispersing oil.”

Nikki Buskey can be reached at 857-2205 or nicole.buskey@houmatoday.com.

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